97 Engine Question
 

Hello all,
I have a 97 Z210 Shabah SS/LE

I am trying to figure out the engine specs and if I have a magnum motor or one of the peanut port engines - and do it with out pulling the intake.
The engine serial number is 0K038027. If I go to the mercruiser site it comes up and says 454 Mag but the it also says 7.4L Bravo 1

Help! I am not understanding this!

Re: 97 Engine Question
 

I am definitely no expert on this, but Bravo 1 is the out-drive model and does not apply to the engine. 7.4 liters is the same as 454 c.i. (7.4 liters x 61 c.i./liter = 452 c.i. actually). So I think they are telling you the same thing.

As to whether you have oval port heads or not, can't help you there.

Re: 97 Engine Question
 

Thanks for the reply! Yes, your correct there, 454 & 7.4L are there same thing, but what I am trying to figure out is if it is a Magnum engine or a regular 454.
Magnum motors had forged cranks, rectangle port heads and roller lifters and the regular 454 (7.4L) had a cast crank, oval port heads and a hydraulic cam.

Roughly also about 30hp difference in them also.

Re: 97 Engine Question
 

I wonder if you can see the difference in the lifters by looking down the push-rod hole?

Now once again, no expert, but isn't the roller lifter restrained from rotating and the hydraulic one is not? If so, you could watch the pushrods and see if they are is spinning while the engine runs.

Re: 97 Engine Question
 

Never thought of that, I had thought about running a scope through the carb into the intake, should be able to tell if they are square port or not.

The engine serial should tell though, I am just confused reading it.

Re: 97 Engine Question
 

See my edited reply above for another way maybe.

Re: 97 Engine Question
 

I think all the push rods can spin. Rollers normally have a lock bar that actually keeps the lifter itself from spinning but not the push rod.

Re: 97 Engine Question
 

But the lifter is what makes them spin. If the lifter isn't spinning, the pushrod wont move much. Normally a hydraulic lifter hole is offset so that it spins and wears evenly.

Re: 97 Engine Question
 

Its possible that might work, but lol - what a mess it would make !

Re: 97 Engine Question
 

Maybe. I know the 5.7 doesn't throw much oil around. I've had the cover off and no oil escapes. But I don't know about the 7.4.

Re: 97 Engine Question
 

Well, after I got some sleep last night the old bulb finally went off. If I pull a valve cover I can use a head casting number to find out what heads are on it. That will tell a lot about the rest of the engine.

I would still think the serial number should tell though.

Re: 97 Engine Question
 

There you go, that should work.